1. Field
Provided is a heating member using a resistive heater, and a fusing apparatus including the heating member.
2. Description of the Related Art
In an electrophotographic imaging apparatus, an electrostatic latent image formed on an image receptor is supplied with toner to form a visible toner image on the image receptor. After transfer of the toner image onto a recording medium, the toner image is fused onto the recording medium. The toner may be prepared by addition of a variety of functional additives, including a coloring agent, into a base resin. The fusing of the toner image involves applying heat and pressure. Energy used in the fusing process makes up most of a total amount of energy used in the electrophotographic imaging apparatus.
In general, a fusing apparatus includes a heat roller and a press roller engaging each other to form a fusing nip. The heat roller is heated by a heat source, such as a halogen lamp. While the recording medium with the transferred toner image passes through the fusing nip, heat and pressure are applied to the toner. In such a fusing apparatus, sequential heat transfer from the heat source to the toner via the heat roller and the recording medium is unlikely to lead to a high heat transfer efficiency. Furthermore, high thermal capacity of the heat roller is disadvantageous in view of a high temperature rise rate of the heat roller.
To address these drawbacks, there has been suggested a fusing apparatus with a sheet heater using hot wires on an external surface of a heat roller. Though the sheet heater is advantageous in terms of a high temperature rise rate, the whole body thereof is unlikely to be uniformly heated. That is, the sheet heater may be locally overheated near hot wires.